Effects Of Medicaid Expansions On Coverage, Prenatal Care, And Health Among American Indian/Alaska Native Women.

American Indian/Alaska Native (AI/AN) women experience distinct political and health care environments and possess unique health risks and resources. We tested whether state Medicaid expansions under the Affordable Care Act were associated with health insurance, prenatal care, health conditions, and birth outcomes among AI/AN women. Using data from the 2010-19 American Community Survey and 2010-19 US birth certificates, we used a difference-in-differences study design to compare outcomes among AI/AN women before and after Medicaid expansions. Medicaid expansions increased the proportion of AI/AN women reporting health care coverage from both Medicaid and the Indian Health Service (IHS), with larger effects among women living in areas with relatively high percentages of reservation land. Consistent with prior research on the broader population of women, Medicaid expansions had no effects on first-trimester prenatal care usage or birthweight among AI/AN women. We found mixed evidence of increased rates of prepregnancy chronic conditions after the expansions. Our findings demonstrate the importance of Medicaid, the IHS, and tribal health systems as sources of health care coverage for AI/AN women of childbearing age.